The Queen's only remaining corgi, who appeared in her 2012 James Bond Olympic sketch, has died just days before Her Majesty's 92nd birthday

Queen Elizabeth II of England, with her pet Corgi dogs, lead members of the Royal Family into Liverpool Street Station in London, Dec. 30, 1966. AP

The Queen's last corgi Willow has died just days before Her Majesty's 92nd birthday.

Her pet was reportedly put to sleep at Windsor Castle on Sunday.

Willow was suffering from a cancer-related illness.

The Queen's only remaining corgi has died just days before Her Majesty's 92nd birthday on Saturday.

According to The Daily Mail, Willow, who was almost 15 years old, was put to sleep at Windsor Castle on Sunday to prevent further suffering from a cancer-related illness.

The corgi is reportedly one of more than 30 Her Majesty has had since 1945.

Willow became famous for appearing alongside Holly, who died 18 months ago, in the Queen's London 2012 Olympic James Bond sketch.

BBC

Willow also appeared in the official portrait to mark the Queen's 90th birthday two years ago.

Corgis have had a relationship with the royals that date back decades, stemming from the Queen's father George VI introducing a dog named Dookie into the family in 1933.

Of the Queen's response to Willow's death, a Buckingham Palace source reportedly said: "She has mourned every one of her corgis over the years, but she has been more upset about Willow's death than any of them.

"It is probably because Willow was the last link to her parents and a pastime that goes back to her own childhood. It really does feel like the end of an era."

The source added: "Willow represents a significant thread running through the Queen's life from her teenage years to her 90s. For many, many years she bred and raised corgis and to think that the last one has now gone is something of a milestone.

"She does not like seeing her dogs suffer and she knows that sometimes putting a dog down is the kindest course of action — although that doesn't make her loss any less."

In this Nov. 19, 1956 file photo, Britain's Queen Elizabeth II, left, and the Queen Mother take their Corgi dogs out for a stroll during a visit to Sandringham, England. AP

The Queen still has has two dorgis - corgi-dachshund crosses - named Vulcan and Candy. She also adopted a corgi named Whisper last year after his owner, a former Sandringham gamekeeper, passed away.

However, Her Majesty decided to no longer breed Pembroke Welsh corgis in 2015, according the Daily Mail, for fear that she "might trip over and hurt herself" — former royal butler Paul Burrell even claimed he "was once knocked unconscious after nine corgis tripped him up."

Buckingham Palace declined to comment to the Daily Mail, though it is understood Willow will be buried in the castle grounds with a headstone calling the pet "a faithful companion of the Queen."